Both House Speaker John Boehner and Treasury Secretary Timothy Geithner dug in their heels on the fiscal cliff debate during appearances on the Sunday talk shows. Boehner blasted the White House proposal as not serious and declared the negotiations to be going "nowhere," while Geithner said the administration would refuse to budge unless Republicans gave in on higher taxes for the wealthiest Americans.

House Speaker John Boehner. EPA/JIM LO SCALZO

But on Fox News Sunday, Boehner (R-Ohio) also told Chris Wallace that Republicans had done their part by putting $800 billion in tax revenue on the table without increasing tax rates:

BOEHNER: Listen, what is this difference where the money comes from? We put $800 billion worth of revenue, which is what he's asking for out of eliminating the top two tax rates.

He repeated the point later in the interview, when Wallace pressed him on how much revenue could feasibly be raised by capping tax deductions:

BOEHNER: The White House knows that the math will work -- to put the kind of revenue on the table that we've been talking about. It won't work if we're trying to get the $1.6 trillion. I'll guarantee you that. But you can put -- we've put the revenue on the table. And, again a dozen different ways to get there without raising tax rates.

WALLACE: And you can get up to what amount?

BOEHNER: Basically the number that we have been --

WALLACE: Eight hundred billion?

BOEHNER: Somewhere in that range.

Republicans have yet to put out a detailed proposal—on tax capping deductions or otherwise—that shows how you would get to $800 billion in revenue, which is only half of the $1.6 trillion revenue target that Obama is asking for.

The White House believes it's impossible to make that target without hitting popular tax breaks like the charitable deduction unless you also target those with incomes below $250,000, citing calculations by the Tax Policy Center.

During the debt-ceiling showdown last year, Boehner had committed to $800 billion in new revenue by overhauling the tax code during his talks with President Obama, but that figure assumed that a simplified tax code with a lower top rate that would spur economic growth—"dynamic scoring" that Democrats have long rejected and that they'd be unlikely to count as real revenue this time around.